/// <summary> /// Reads and parses a WKT-formatted projection string. /// </summary> /// <param name="wkt">String containing WKT.</param> /// <returns>Object representation of the WKT.</returns> /// <exception cref="System.ArgumentException">If a token is not recognised.</exception> public static IInfo Parse(string wkt) { IInfo returnObject = null; StringReader reader = new StringReader(wkt); WktStreamTokenizer tokenizer = new WktStreamTokenizer(reader); tokenizer.NextToken(); string objectName = tokenizer.GetStringValue(); switch (objectName) { case "UNIT": returnObject = ReadUnit(tokenizer); break; //case "VERT_DATUM": // IVerticalDatum verticalDatum = ReadVerticalDatum(tokenizer); // returnObject = verticalDatum; // break; case "SPHEROID": returnObject = ReadEllipsoid(tokenizer); break; case "DATUM": returnObject = ReadHorizontalDatum(tokenizer);; break; case "PRIMEM": returnObject = ReadPrimeMeridian(tokenizer); break; case "VERT_CS": case "GEOGCS": case "PROJCS": case "COMPD_CS": case "GEOCCS": case "FITTED_CS": case "LOCAL_CS": returnObject = ReadCoordinateSystem(wkt, tokenizer); break; default: throw new ArgumentException(String.Format("'{0'} is not recongnized.", objectName)); } reader.Close(); return(returnObject); }
/// <summary> /// Returns a <see cref="AngularUnit"/> given a piece of WKT. /// </summary> /// <param name="tokenizer">WktStreamTokenizer that has the WKT.</param> /// <returns>An object that implements the IUnit interface.</returns> private static IAngularUnit ReadAngularUnit(WktStreamTokenizer tokenizer) { tokenizer.ReadToken("["); string unitName = tokenizer.ReadDoubleQuotedWord(); tokenizer.ReadToken(","); tokenizer.NextToken(); double unitsPerUnit = tokenizer.GetNumericValue(); string authority = String.Empty; long authorityCode = -1; tokenizer.NextToken(); if (tokenizer.GetStringValue() == ",") { tokenizer.ReadAuthority(ref authority, ref authorityCode); tokenizer.ReadToken("]"); } return(new AngularUnit(unitsPerUnit, unitName, authority, authorityCode, String.Empty, String.Empty, String.Empty)); }
/// <summary> /// /// </summary> /// <param name="tokenizer"></param> /// <returns></returns> private static IPrimeMeridian ReadPrimeMeridian(WktStreamTokenizer tokenizer) { //PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]] tokenizer.ReadToken("["); string name = tokenizer.ReadDoubleQuotedWord(); tokenizer.ReadToken(","); tokenizer.NextToken(); double longitude = tokenizer.GetNumericValue(); tokenizer.NextToken(); string authority = String.Empty; long authorityCode = -1; if (tokenizer.GetStringValue() == ",") { tokenizer.ReadAuthority(ref authority, ref authorityCode); tokenizer.ReadToken("]"); } // make an assumption about the Angular units - degrees. IPrimeMeridian primeMeridian = new PrimeMeridian(longitude, AngularUnit.Degrees, name, authority, authorityCode, String.Empty, String.Empty, String.Empty); return(primeMeridian); }
/// <summary> /// /// </summary> /// <param name="tokenizer"></param> /// <returns></returns> private static IProjectedCoordinateSystem ReadProjectedCoordinateSystem(WktStreamTokenizer tokenizer) { /*PROJCS[ * "OSGB 1936 / British National Grid", * GEOGCS[ * "OSGB 1936", * DATUM[...] * PRIMEM[...] * AXIS["Geodetic latitude","NORTH"] * AXIS["Geodetic longitude","EAST"] * AUTHORITY["EPSG","4277"] * ], * PROJECTION["Transverse Mercator"], * PARAMETER["latitude_of_natural_origin",49], * PARAMETER["longitude_of_natural_origin",-2], * PARAMETER["scale_factor_at_natural_origin",0.999601272], * PARAMETER["false_easting",400000], * PARAMETER["false_northing",-100000], * AXIS["Easting","EAST"], * AXIS["Northing","NORTH"], * AUTHORITY["EPSG","27700"] * ] */ tokenizer.ReadToken("["); string name = tokenizer.ReadDoubleQuotedWord(); tokenizer.ReadToken(","); tokenizer.ReadToken("GEOGCS"); IGeographicCoordinateSystem geographicCS = ReadGeographicCoordinateSystem(tokenizer); tokenizer.ReadToken(","); IProjection projection = ReadProjection(tokenizer); IUnit unit = ReadLinearUnit(tokenizer); string authority = String.Empty; long authorityCode = -1; tokenizer.NextToken(); List <AxisInfo> axes = new List <AxisInfo>(2); if (tokenizer.GetStringValue() == ",") { tokenizer.NextToken(); while (tokenizer.GetStringValue() == "AXIS") { axes.Add(ReadAxis(tokenizer)); tokenizer.NextToken(); } if (tokenizer.GetStringValue() == "AUTHORITY") { tokenizer.ReadAuthority(ref authority, ref authorityCode); tokenizer.ReadToken("]"); } } //This is default axis values if not specified. if (axes.Count == 0) { axes.Add(new AxisInfo("X", AxisOrientationEnum.East)); axes.Add(new AxisInfo("Y", AxisOrientationEnum.North)); } IProjectedCoordinateSystem projectedCS = new ProjectedCoordinateSystem(geographicCS.HorizontalDatum, geographicCS, unit as LinearUnit, projection, axes, name, authority, authorityCode, String.Empty, String.Empty, String.Empty); return(projectedCS); }